I believe I now understand how this scam works.
There was someone who almost got scammed using the wallet's watchlist feature:
https://bitcointalk.org/index.php?topic=2948841.0If you read my post on that thread, you will understand how they do it.
- Tests by video call
- Proof bitcoins funds by Skype or Zoom video call
No wonder this guy claims he has 100 to 2500 or even more BTC. Read my post on the link above and see how the scam works.